Regulating mechanism to control the feeding of cartridges in belt-fed machine guns



E. SAETTER-LASSEN REGULATING MECHANISM TO CONTROL THE 'FEEDING OF' CARTRIDGES IN BELT-FED MACHINE GUNS .July 2, 1957 Unite REGULATING MECHANISM T CONTROL THE FEEDING 0F CARTRIDGES IN BELT-FED MACHINE GUNS Erik Saetter-Lassen, Gentofte, Denmark Application November 6, 1952, Serial No. 319,061

Claims priority, application Denmark November 17, 1951 Claims. (Cl. 89-33) In the known machine guns with such regulat-ing mechanism the curved bar is pivoted on the lower side of the lid placed on top of the receiver and closing the opening of the lock mechanism so that the curved bar will be entirely covered and make its turning movements inside the space protected by the lid.

This already known arrangement suffers from various drawbacks. Furthermore, in machine guns of already known construction the curved bar is aixed to the lid which must therefore be made considerably longer than would otherwise be necessary wherefore it will become rather heavy and unwieldy and at the same time relatively sensitive to strains. These drawbacks are obviated by the invention according to which the curved bar is pivoted on the fixed part of the recevier, whereas the elements moved by the curved bar in a manner known per se are mounted on a hinged lid covering the feed mechanism and the feed opening for the cartridge and fitted on the receiver.

By having the curved bar pivoted on the fixed part of the receiver it will be possible to make the lid considerably shorter. As the length of the curved bar must at least be equal to the length of the motion of the breechblock between its two extreme positions and the curved bar out of regard to space must be placed behind the parts belonging to the slide mechanism for the cartridge feed, the location of the curved bar in the lid would entail an extension of the latter by almost the full length of the curved bar. This extension which is necessary in the already known constructions and which makes the lid heavy and unhandy and in open condition vulnerable to impacts, as mentioned in the foregoing, may be entirely obviated by the present invention according to which the curved bar is situated to the rear of the hinged lid of the receiver.

In the mechanism according to the present invention the lgroove of the curved bar is open to the rear, so that the tappet engaging the groove by a rearward motion may be drawn out of the groove and released from the curved bar. Thus, the curved bar will not prevent the breech-block from being pulled to the rear and disengaged from the receiver and the lid need not be opened in order that the breech-block may be pulled out to the rear and reinserted.

States Patent() In order by the pivoting of the curved bar on the the invention expediently be provided with a pivot head WCC crossed by the groove and mounted on a suitable bearing which permits the curved bar to swing on the axis of the pivot-head and which is situated in such a plane `that the strains of the tappet against the curved bar will not subject it to any oblique strain. As the curved bar is arranged to swing on itsrear end, the removed breechblock may at any time be reinserted regardless of the position of the curved bar at that moment, as the rearward opening of the groove will at all times coincide with the slit in the receiver for the tappet of the breech-block. In order further to ensure that the moving parts mounted on the hinged lid will correctly engage the curved bar mounted on the fixed part of the receiver when the lid is closed, the parts actuated by the curved bar and mounted on this hinged lid may according 4to the invention be spring-loaded in such a manner that they will tend to assume the position corresponding to the rearmost position of the breech-block.

The accompanying drawings show an embodiment of a regulating mechanism according to Ithe invention mounted on a machine gun of the gas pressure type, in which Fi'g. 1 shows a vertical, longitudinal section through part of the gun with the regulating mechanism,

Fig. 2 the lid of the receiver with the parts thereon mounted seen from below,

Fig. 3 -the curved bar in side elevation,

Fig. 4 the curved bar seen from below,

Fig. 5 the curved bar seen from above, and

Fig. 6 the curved bar viewed from its forward end.

The receiver of the gun is designated 1, whereas 2 designates the lid hinged to it with latch 3. In the lid, two cartridge'feed slides 4 and 5 are mounted, shiftable in transverse direction and each connected by a link to the respective ends of a pivoted operating lever 6 by the reciprocating movements of which the Vtwo slides are moved in opposite directions. At the rear end of the operating lever a tappet 7 is mounted, engaging the bifurcated end of an intermediate lever 8 which is likewise pivoted in the lid and the other end of which is also bifurcated and situated just inside the rear end of the lid 2. The lid further holds a plate-shaped, springloaded tumbler 9 turnably mounted on an axle 10 and by means of a `Spring pressed downwards to hold in place the cartridges successively feed into the gun. The axle 10 is at its ends carried through bearing holes in flanges 11 of the lid and is immediately outside one flange provided with a shoulder 12. The plate of the tumbler is bent around the axle 10 and does not fill the entire space between the two anges 11, a compression spring 13 being inserted between the edge of the tumbler and one of the flanges 11 on the axle 10, so that the tumbler and, by means of the shoulder 12, also the axle are pushed as far as possible over against the opposite flange 11. By shifting by hand the tumbler 9 and the axle 10 in such a way as to compress the spring 13, the axle may be released first from one and then from the other flange 11 and together with the tumbler 9 be removed from the gun. In the receiver 1 the breech-block 14 may reciprocate. The breech-block is at its rear end provided with an upward tappet 15 projecting upwards through a longitudinal slit in the receiver and into the downward groove of a curved bar 16 pivoted in the top of the receiver. This curved bar is shown in detail in Figs. 3-6 and consists of a trough-shaped, flanged strip or plate 17, the side flanges 18 of which form the groove 19 which is carried through a block 20, forming a pivothead which is fastened to the extended bottom of the trough, the plate strip being joggled at this place to give room for the metal of the pivot-head 20 in the way of 3 the groove. The pivot-head forms the rearmost end of the curved bar. At the forward end of the curved bar the plate strip 17 has a laterally projecting web 21 troughshaped in the opposite direction and serving partly to prevent the curved bar in its swinging movements from fouling the edges of the slits in the receiver and partly by impinging against a fixed stop, not shown, to limit the lateral swing of the curved bar. On top of this end of the curved bar a tappet 22 is provided, supported by a mounting 23 and encased by a turnable roller 24. When the gun is in the assembled state this roller engages the rearmost bifurcated end of the intermediate lever 8 and when the curved bar by the reciprocating motion of the breech-block is made to swing to the sides on the axis of the pivot-head 20 by the tappet 15, the said pivot head being mounted in a recess in the receiver symmetrical on its slit for the passage of the tappet 15, this will make the intermediate lever 8 and thus the operating lever 6 swing to and fro, whereby the feed slides 4 and 5 will be moved in step with Ithe movements of the breech-block. The insertion of the intermediate lever 8 in the connecting mechanism between the curved bar and the operating lever serves, inter alia, to make possible the rearward placing of the curved bar, so that after the opening of the lid it will not project so far forward over the cartridge seat, etc. as to cause trouble. Likewise the intermediate lever may magnify the motion by transmission of the oscillating movements of the curved bar to the operating lever.

In order to ensure that when the lid has been opened the rear end of the intermediate lever 8 will re-engage the roller 24, a spring 25 is mounted on the lid and actuates the intermediate lever tending to carry it to the side corresponding to the rearmost position of the breech-block. When the lid is closed it will only be necessary to see that the breech-block is in that position and the intermediate lever will on the closing of the lid engage the curved bar. The diiiicult adjustment of the parts necessary in the constructions hitherto known will thus be avoided.

For protection of the curved bar a cover-plate 26 is fitted to the receiver, which cover-plate at the same time forms a rest for the rearmost end of the lid.

I claim:

l. Regulating mechanism to control the feeding of cartridges in belt-fed machine guns having a receiver and a reciprocating breech-bolt, said mechanism including a lid hinged to said receiver, two feeding slides laterally CII slidable mounted in said lid, means cooperating with said slides to make them move reciprocally in opposite directions to each other, said means comprising a curved bar and a swingable lever, said lever being mounted in said lid and which lever, when the lid is closed, is operatively coupled to one end of said bar, said bar being laterally swingable and having the other end thereof pivoted to said receiver, said curved bar also having at its underside a correspondingly curved groove, and an upward tappet on said reciprocating breech-bolt engaging said groove, said tappet during the reciprocating movement of the breech-bolt sliding along said groove, thereby causing said curved bar to oscillate and to activate said swingable lever operatively coupled to the end of said bar.

2. Mechanism according to claim l, wherein said curved bar, at its pivoted end, is provided with a pivot head crossed by the groove on the underside of said bar and a suitable bearing on the receiver mounting said head, said pivot head and bearing being situated at such a level relatively to the operative parts of said bar that the lateral forces exerted on said bar during its operation are substantially situated in one horizontal plane, in order to avoid 'transverse tilting action on said bar.

3. Mechanism according to claim l, wherein said curved bar is situated to the rear of said lid and is at its front end operatively coupled to said swingable lever.

4. Mechanism according to claim 1 and also including an intermediate lever, wherein the swingable lever operatively coupled to one end of said curved bar is coupled to said feeding slides via said intermediate lever, said last lever being swingably mounted in said lid.

5. Mechanism according to claim l and also including a spring, wherein the means mounted in said lid for the operation of said feeding slides and actuated by said curved bar are submitted to the action of said spring, said spring being mounted in said lid and tending 'to `bring said means into a position corresponding to the position of the curved bar, when said breech-bolt is in its rearmost position.

References Cited in the tile of this patent FOREIGN PATENTS France May 30, 1944 Great Britain Aug. 27, 1952 OTHER REFERENCES 

